背景：体组织温度测量包括有损测温和无损测温，有损测温难以整体测出组织的三维温度场，而无损测温尚处于研究阶段，离临床应用还有一定距离，理想的做法是建立数学及物理模型并通过计算来预测和模拟肿瘤的热治疗。目的：获得股骨肿瘤热疗时肿瘤及周围组织的三维温度分布规律。方法：以热传递理论、Laplace方程和Pennes生物热传导方程为基础，在设定骨组织热物性参数，给定边界和初始条件的情况下，利用有限元分析方法计算股骨肿瘤热疗时的三维温度分布规律。结果与结论：股骨组织具有很好的阻碍热传导作用，股骨温度等值线在三维空间以热源为中心成椭球形分布，离热源越近温度梯度越大。3个方向上50℃等温线长径不同，横断面最大，冠状面次之，矢状面最小。由此可知，肿瘤热疗中，温度在股骨3个方向上温度的传递能力不同，对肿瘤的灭活半径也就不同。所以热疗时即使肿瘤形状规则也需要多区域加热，而不只是在肿瘤中心加热，否则会导致肿瘤组织有残留或者破坏正常组织。%BACKGROUND:Temperature measure methods of human tissue include destructive measurement and nondestructive measurement. Destructive measurement cannot measure three-dimensional (3D) temperature field and nondestructive measure is stil in the research stage. It is better way to build a mathematical and physical model to predict and simulate femur tumor hyperthermia. OBJECTIVE:To obtain the three-dimensional temperature distribution of femur and its surrounding tissues during tumor hyperthermia. METHODS:3D temperature distribution was obtained by using finite element method on the basis of heat conduction theory, Laplace equation, Pennes bio-heat transfer equation, thermo physical parameters of bone tissues, the boundary condition, and initial conditions. RESULTS AND CONCLUSION:The femur had good hinder effect to heat transfer. Femoral temperature curve in the 3D space showed el ipsoid distribution with heat source as the center;the closer from heat source, the greater the temperature gradient was. The three major diameters of temperature isoline were different at 50℃, which is maximum in cross section and minimum in the sagittal plane. In the three directions of the femur, transfer capability of temperature was different, so the radius of the inactivation of the tumor was also different. Because the 3D temperature space distribution of femur is asymmetry during hyperthermia, the necessary method is to use more than a heat source in order to avoid residual cancer tissue or destructive normal tissue.
展开▼
